Lecture 17: More Tableau

Tableau

• Last time we got some basic graphs going and got familiar with the software
• This time we’ll go a little deeper!
• First, working our way around the decoration and customization options
• Then, making some more complex graphs with Table Calculations and Shelves

Decoration

• We can adjust the presentation of most elements of the graph by double clicking on them, Excel style
• For example, axes
• From here we can adjust tick marks, scale, consistency of scale across multi-part graphs, and numerical formatting, as well as things like “include 0 on the axis or no?”

Formatting Numbers

• We can also see on the left when we click on an axis the “Scale” segment
• We can set things like percentages being .1 or 10%, or the units of the variable (like $)
• (If you’re having trouble, RIGHT-click the axis and hit Format)

Decoration

• Let’s take the example worksheet and walk through adjusting the axis
• Look at Sheet 1
• Make the y-axis tick marks percentages with one decimal place
• And make the x-axis only have ticks on days 0, 10, 20, 30.
• Also change axis titles to “Day of Month” and “Percent Cancelled

Decoration

Decoration

The Result

Colors

• We can make a variable be distinguished by color by dragging it to the Color part of the Marks pane
• (This will add color to the variable, not its position, so drag it from the left variables pane, not away from its column/row if it’s there!)
• Then click Color to manually adjust the colors used or pick a palette, or pick opacity

Other Axes

• Just like the axes in our ggplot2 aes()thetic, we can similarly drag variables to be used on the Size, Label, etc. axes
• Having variables just on these axes and not Column or Row will create different kinds of output - Labels-only will give a table, for example
• Also, not really an axis, but by clicking data points we can zoom in on them, exclude them, or exclude others
• The Marks card is the home of these, and we can edit things directly there

Decoration

• On Sheet 2
• Let’s color our data by Cancelled
• And make the size differ by Distance
• And exclude flights before 3AM
• Make an annotation of an area (What story does this tell?)
• And title it “Departure Times and Delays”

Decoration

Table Calculations

• By clicking the down-arrow on a numeric variable on an axis, we can change it from being presented raw to being presented relative to other stuff
• We already covered how we can make it a calculation/summary: mean, median, etc.
• Table Calculations extend the analysis to make the presentation relative to other calculations
• i.e. changing a line graph from the values to growth-from-previous-period, or moving average
• Or making a bar graph percent-of-total, or rank

Table Calculations

• Let’s change the bar graph from count to percent of total
• Now you change the line graph from percent to change-since-previous
• (Also, while we’re at it, add data point labels to the line graph)
• (And right-click an empty space to add an annotation)

Other Down-Arrow Adjustments

• We can also use this down-arrow to sort
• For example, sorting a bar by its height, or the value of another variable
• You can do this using another variable directly, or a table calculation (like a COUNT) of a variable

Getting More Complex

• If you want to do more detailed adjustments to variables, things like complex created variables, you can do so with Create Calculated Field
• But this does require that you learn the Tableau coding system. You can Google for how to do stuff, but it’s often easier just to do it in R and export to Tableau (same as with joins/etc.)
• One exception is if you just want a basic condition checked
• IF [X] == Value THEN "A" ELSE "B" END
• Can also use ELSEIF for more-flexible grouped variables than with Groups

Animation

• You can do basic animations by adding a variable to “Pages”; this will make a slideshow going through each value
• This is only one kind of animated graph but it is very easy to make! Let’s try one.

Sharing Work

• Tableau workbooks can be saved and shared
• If you want them to be interactive for someone without Tableau, have them use Tableau Reader
• Or just a static image with Worksheet \(\rightarrow\) Export
• Or make a dashboard (we’ll get to that next time)!

Sharing Work

• If you’re sharing with someone who has Tableau, and your data isn’t enormous, use a packaged workbook.
• This will bundle the data set in with your work so they can actually open it, making a .twbx file
• If you don’t do this and just send a .twb then they won’t be able to see your work at all!!
• If you turn in your Tidy Tuesday homework as a .twb I won’t be able to read it and you’ll have to resubmit.

Practice

• Let’s walk through creating the graph on the following slide…

Practice

• Now you recreate this graph

Practice

• Make your own graph with this data